JPS6070030A - Production of freeze-dried lemon - Google Patents

Abstract

PURPOSE:To produce a freeze-dried lemon, capable of retaining the beautiful shape when cut into round slices, and having improved flavor and taste and high keeping quality without bitterness. CONSTITUTION:A raw lemon is dipped in hot water for 30sec-4min to remove turpentine oil from the rind, and the resultant lemon is cut to round slices having about 2mm. thickness and preferably dipped in a an aqueous solution with 1- 10% saccharide concentration containing sodium ascorbate for about 10-30min, drained and then freeze-dried.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing freeze-dried lemons that retain their beautiful shape when sliced, have a good aroma and taste, are not bitter, and have a high shelf life.

Sliced lemons are usually 24 to 26 pieces per lemon.
Each lemon is cut to a thickness of about 2 fins, but if it is freeze-dried for preservation, the moisture will be lost and the sandbags will easily fall off. It is difficult to maintain the beautiful shape when Furthermore, when freeze-dried lemon slices are used, turpentine oil, which is a bitter component contained in the epidermis, leaches into black tea, etc., giving it an abnormally bitter taste. Furthermore, freeze-drying may destroy some of the vitamin C in sliced lemons, and the aroma and other properties are also likely to be lost.

The inventors of the present invention have conducted extensive studies to resolve the above-mentioned disadvantages of freeze-dried sliced lemons, and have found that by performing a specific treatment before freeze-drying, they can retain their beautiful shape when cut into slices, as well as maintain their aroma and taste. It has been found that freeze-dried lemons with good taste, no bitterness, and long shelf life can be obtained.

The present invention has been made based on the above findings, and provides a method for producing freeze-dried lemons, which comprises immersing sliced lemons from which turpentine has been removed in an aqueous solution of sugars and then freeze-drying them. It is.

Hereinafter, the method for producing freeze-dried lemon of the present invention will be described in detail based on its preferred embodiments.

In carrying out the present invention, first, sliced lemons are prepared from which turpentine has been removed from the epidermis.

For this preparation, fresh lemons are usually first treated with boiling water, preferably immersed in boiling water, to remove the turpentine in their skins. Turpentine oil, which is a bitter component, is not a major concern in the case of fresh lemons, but it has a very strong bitter taste after freeze-drying. The turpentine is eluted and removed. When soaking fresh lemons in boiling water to remove turpentine oil, the soaking time is 30 seconds to 4 seconds.
minutes, preferably 1 to 2 minutes. Next, the fresh lemon that has been treated to remove turpentine as described above is sliced into rounds to form lemon slices. The preferred thickness of the lemon slices is about 21 mm.

Next, the lemon slices are soaked in an aqueous solution of sugar. Examples of the saccharide in this case include sorbitol, glucose, mannose, fructose, sucrose, etc., and sorbitol and sucrose are preferably used. The sugar concentration in the aqueous solution is
Preferably 1 to 10%, more preferably 5%
Before and after.

Further, the soaking time of the lemon slices is preferably 10 minutes or more, and about 30 minutes. By immersing the sliced lemon in the aqueous solution of sugars in this manner, it is possible to prevent the sandbags from falling off after freeze-drying and to allow the sliced lemon to maintain its beautiful shape when sliced.

In other words, even if the lemon slices are thinly sliced as described above, the sand bags easily fall off, and especially when the lemon is freeze-dried, the moisture evaporates, making the sand bags even more likely to fall off. When lemons are soaked in an aqueous solution of sugars, the sugars can fill the gaps between the sandbags and strengthen the bond between the sandbags, thus preventing the sandbags from falling off after freeze-drying. can do. In addition, sugars are added to the lemon slices by soaking them in an aqueous solution of sugars, so if you use the lemon slices directly for tea after freeze-drying, the taste will be mellower and more flavorful. is twitching.

In addition, it is preferable that sodium ascorbic acid (vitamin C) is dissolved in the aqueous solution of sugars in a concentration of 0.1 to 0.3%. This can reinforce and fortify the vitamin C lost from the lemon slices during freeze-drying. Furthermore, since vitamin C has an antioxidant effect, it is possible to prevent the product from oxidizing.

Thereafter, the lemon slices soaked in sugar are drained, frozen, and further freeze-dried to obtain the freeze-dried lemon (
The product of the present invention) is obtained. Preferred freeze-drying conditions are 0.1-
0.5) Under vacuum of Torr, shelf temperature 20-40℃
It is.

When the thus obtained product of the present invention is made into a product, it is usually
It can be vacuum punctured by vacuum packaging, dehumidified by adding drying material, or a combination of these can be used to create a long-term storage product that can be easily used.

Incidentally, the treatment for removing turpentine from the epidermis is preferably carried out before slicing as described above, but it may also be carried out after slicing. Further, the treatment for removing turpentine oil is not limited to the hot water treatment as in the embodiment, but is not limited to any means that can remove turpentine oil.

As described above, according to the method for producing freeze-dried lemon of the present invention, prior to freeze-drying the lemon slices, the lemon slices that have been treated to remove turpentine are prepared, and the prepared lemon slices are placed in an aqueous solution of sugars. Because it is soaked, it is possible to obtain freeze-dried lemons that retain their beautiful shape when sliced, have a good aroma and taste, are not bitter, and have a long shelf life. By melting soda and adding ascorbic acid sorta to lemon slices, effects such as strengthening the vitamin C in the lemon slices that are destroyed during freeze-drying and preventing oxidation of the product can be achieved.

Examples of the present invention are shown below.

6- Example M class fresh lemons were heated by immersing them in boiling water for 1 minute and 30 seconds, and then immediately cooled in running water to remove water droplets on the surface.

Next, the fresh lemon subjected to the above treatment was sliced into rounds with a thickness of approximately 2 fi using a knife (or a slicer may be used).

The lemon slices were immersed in a 5% aqueous sorbitol solution containing 0.15% sodium ascorbic acid for 30 minutes, then lightly drained and freeze-dried to obtain a product of the present invention.

On the other hand, in parallel with the above process, sliced fresh lemons into rounds approximately 2H thick without boiling them.
A control product was obtained by immediately freeze-drying.

Note that the shelf temperature during freeze-drying of the products of the present invention and the control product was 30°C.

The comparison results between the product of the present invention and the control product are as shown in the table below.

−Table 1

Claims (5)

[Claims] (1) A method for producing freeze-dried lemons, which comprises immersing sliced lemons from which turpentine has been removed in an aqueous solution of sugars, and then freeze-drying them. (2) The method for producing freeze-dried lemon according to claim (1), wherein the aqueous solution has a saccharide concentration of 1 to 10%. (3) The method for producing freeze-dried lemon according to claim (2), wherein sodium ascorbic acid is contained in the aqueous solution of ¥II. (4) The method for producing freeze-dried lemons according to claim 411, wherein the turpentine removal treatment is carried out by immersing the cherry blossom lemons in hot water before slicing the cherry blossom lemons into rounds. (5) The method for producing freeze-dried lemons according to claim (4), wherein the dried lemons are immersed in boiling water for 30 seconds to 4 minutes.